This invention relates to utility pole and tree climbers. Tree and pole climbing aids have been used since the late 1800's. Since that time several patents have been granted for variations of climbing spurs which had as one of their objectives the reduction of weight of the units. The combination of inherent weight of the climbing spurs and the added pull on the knee joint necessitated during the extraction of the gaff or spur from the tree or pole adds much to the discomfort of the individual doing the climbing.
U.S. Pat. No. 237,275 granted Feb. 6, 1881 was an early version of a pole climbing aid. U.S. Pat. No. 938,905 dated Nov. 1909 attempted to achieve lightness but it failed to protect the ankle of the wearer. Later patents such as U.S. Pat. No. 2,391,810 dated Dec. 24, 1945; U.S. Pat. No. 2,604,250 dated July 22, 1952; and U.S. Pat. No. 3,867,998 of Feb. 25, 1975 each incorporated a vertical bar strapped to the foreleg of the wearer. These climbers use a short solid gaff or spur to engage the pole or tree being climbed.
U.S. Pat. No. 4,153,139 dated May 8, 1979, a Non Adjustable Climber, achieves lightness by incorporating a pressed steel vertical bar and a hollow gaff or spur which uses a cutting action to penetrate the tree or pole as distinguished from the expansion forces in the penetration by the solid spur or gaff. The primary stated purpose being the reduction of overall weight of the climbing spurs as well as the effort required to insert and extract the gaff from the tree or pole and thereby reducing the strain and fatigue of the wearer.
U.S. Pat. No. 2,428,075 filed May 10, 1946 is a pole climbing harness which uses thigh band and foot harness each incorporating a rope with a clove hitch for traversing a vertical pole.